In high temperature furnaces employed in the heat processing of materials and products, electrical heating elements are usually employed. A plurality of individual heating elements can be provided along the length of the furnace, the elements being electrically energized to provide heating of the furnace chamber. Different combinations of the heating elements can be arranged and energized to provide zones of different temperature. Furnace heaters are also known which are effectively continuous in length and comprise an electrical resistor ribbon wound in a helical or circuitous path and which is provided in encircling or confronting relationship with the furnace chamber. These ribbon-type heaters are supported on an insulative structure which adds to the overall weight and thermal inertia of the heater assembly. In addition, the heater is comprised of a single resistance ribbon, and the entire heater assembly is heated to the same temperature. For different temperature zones, a separate heater would be provided for each zone. Moreover, a break in the ribbon will result in an open circuit of the entire heater.